Overview

Gastrointestinal (GI) motililty refers to the movement of food from the mouth through the throat, esophagus, stomach, small and large intestines and out of the body.

The contraction of muscles in the intestinal tract propels food forward or aids in digestion by increasing the mixing of food. When the muscles contract in a sequential and synchronized fashion, they push food (usually) forward: an act known as peristalsis. Occasionally the muscles, by design and particularly in the stomach, contract more randomly, which aids in the mixing and breakdown of food.

When the movement of food through the tract is impaired in some way, a gastroenterologist who specializes in gastrointestinal motility disorders can help.

The Phelps Memorial Hospital Gastrointestinal Motility Center offers state-of-the-art diagnostic and therapeutic approaches to evaluate accurately and to treat properly a broad range of gastrointestinal motility disorders. The Center’s physicians and nurses have specialized training in the full spectrum of motility disorders, and the team is dedicated to each patient’s well being.

Constipation

Constipation is, strictly speaking, a symptom and not a disease. The definition of constipation is broad, but generally people in the United States have a bowel movement at least every three days. Constipation is associated with discomfort, straining, bloating and the sensation of a full colon. Constipation is exceedingly common, with more than 4 million Americans having frequent constipation and a much larger number experiencing constipation occasionally.

The most common causes of constipation are diet related, particularly the consumption of either insufficient fiber or fluids or both. Lack of exercise also contributes to constipation, as do certain medications. Some diseases, including neurologic disorders such as Parkinson’s disease and metabolic disorders such as diabetes or hypothyroidism, are also common culprits.

Esophagus - normal function

Within the entire gastrointestinal tract, there are distinct zones of muscles and tissue with individual and somewhat independent functions: the esophagus, stomach, small intestine and large intestine or colon. While there are similarities between each section of the GI tract, there are also differences relating to the different tasks that they have. Each of these areas is separated by sphincter muscles which helps ensure that food will progress forward and not reverse course.

Most prominent among the sphincter muscles are the Upper Esophageal Sphincter muscle, separating the mouth/throat (oropharynx) from the esophagus and the Lower Esophageal Sphincter muscle separating the esophagus and the stomach.

Normal Function:

The esophagus acts quite simply as a conduit, transporting food from the mouth to the stomach. No true digestion takes place in the esophagus. To accomplish its task, an intricate interplay between multiple muscles takes place. The mouth muscles, including the tongue, thrust food to the esophagus. The upper esophageal sphincter (UES) opens, allowing passage of the food, and then closes tightly to prevent backward spill. The esophagus then contracts with powerful, sequential muscle contractions, pushing food down. At the other end of the esophagus, the lower esophageal sphincter (LES) opens, making way for the food, and then it, too, contracts to prevent backward reflux of food.

Normally, the UES and LES only relax or open when food is present above them (in the mouth or in the esophagus respectively) and normally the esophagus itself remains quiet, without contractions, except when food is present.

Dysphagia

Dysphagia simply means ineffective swallowing. There are multiple possible causes of this condition. The symptoms include the feeling that food is not going down properly, that food is getting stuck, that there is a sensation of food that is left behind. The first concern with these symptoms is that, in fact, there is no blockage that is preventing the passage of the food, such as a fibrous stricture or ring as can sometimes be seen in people who have acid reflux disease (see below) or even tumors or growths.

If a physical blockage is ruled out (usually with an endoscopy or possibly an x-ray study), then a muscle dysfunction becomes more likely. The problems may include an abnormality in the way that the food is presented to the esophagus by mouth and tongue muscles, or in the relaxation of the UES. Sometimes, for instance, people with even minor strokes can have difficulty with this phase of the swallowing act. Typically, this area is assessed through the Phelps Speech and Swallowing Centers.

Dysphagia may also result from a dysfunction of the esophageal muscles. If the normal, sequential muscle contractions become disrupted, either by no longer contracting sequentially but rather contracting all together or by contracting too weakly, the food will not go down smoothly and the symptoms of dysphagia will result. Similarly, if the LES does not relax and open appropriately, in effect, a mechanical blockage will result and, again, symptoms of dysphagia. This latter condition is known as achalasia. These problems are typically assessed by an esophageal manometry study.

Gastroesophageal reflux disease (GERD)

Heartburn, or GERD, is the most common symptom in the esophagus and is caused by the reflux of stomach contents into the esophagus. This will occur particularly if the LES malfunctions. In some cases, the LES muscle is simply weak, not creating a tight seal between the stomach and esophagus and thus allowing reflux to occur. In other cases, the LES will relax inappropriately when there is no food in the esophagus. In either case, the presence of a hiatal hernia increases the risk of reflux.

The most common form of reflux is acid reflux, which can cause the classic symptoms of burning in the chest, though frank pain, hoarse voice, bad taste in the mouth or bad breath and even dysphagia from an acid induced stricture may occur. These problems are typically assessed initially by an upper endoscopy test, then an esophageal manometry study, and if necessary, an esophageal pH study to measure the presence of acid in the esophagus.

Chest pain - functional or non-cardiac

Either reflux or muscle dysfunction may result in chest pain that is not a typical heartburn pain and may easily be confused with that stemming from the heart. As a consequence, the initial evaluation will always center upon possible cardiac disease. If the heart as a cause is successfully ruled out, then the focus will turn to possible esophageal causes. Evaluation will typically include an endoscopy, probable manometry and possibly a pH study.

Stomach

Normal Stomach Function:

The normal muscle function in the stomach involves both somewhat disordered muscle activity that aids in the breakdown of food and its mixing and the more controlled sequential contractions that push food out of the stomach. The emptying of the stomach is meant to be a relatively gradual and controlled process. At the end of the controlled emptying, strong contractions will sweep all remnant particles out of the stomach and into the small intestine for further digestion and absorption.

Delayed Gastric Emptying (Gastroparesis):

The symptoms of delayed emptying include nausea, vomiting, feeling full, early satiety, and even bloating and pain. Of course, these symptoms may be caused by a variety of problems unrelated to gastroparesis or delayed emptying.

Evaluation often begins with simple laboratory tests followed by an endoscopy test to assess for conditions such as ulcers or severe gastritis or even tumors, which can cause significant symptoms and even actual delayed emptying. Abdominal CT scans may be necessary, depending upon the whole picture. If necessary, the gastric emptying process may be measured via a gastric emptying study involving the patient eating a labeled meal whose progress through the stomach and small intestine may be monitored.

Occasionally patients will suffer not from delayed emptying but from too rapid emptying of the stomach. This condition usually occurs when the person has had surgery and is diagnosed primarily by eliminating other causes of symptoms and by the patient’s history, but gastric emptying studies can sometimes be useful.

Functional Dyspepsia:

A related symptom, sometimes called functional dyspepsia, involves pain or discomfort in the center of the abdomen. Other common symptoms include bloating, mild nausea, fullness and malaise. The possible etiologies are numerous but studies have shown that a mild delay in gastric emptying or improper expansion of the stomach may occur in at least one third of patients. Work-up depends greatly upon the individual patient’s circumstances but may include laboratory tests, endoscopies, CT scans and gastric emptying studies.

Summary:

Appropriate evaluation of a variety of conditions including dysphagia, reflux, pain and nausea may require manometry, pH and emptying studies to understand completely and to most effectively plan a treatment program.

Fecal incontinence

Fecal incontinence is a common condition which, depending upon the definition used, occurs in 2 to 15% of people. Its incidence increases with age and its frequency is similar in men and women. The effects can be quite mild but lamentably often have a devastating impact upon the patient.

The primary causes of fecal incontinence include liquid stool (liquids require significantly more anal sphincter muscle contraction to control than do solid stools), decreased anal sphincter muscle tone and strength, decreased rectal sensitivity (which can result in excessive build up of stool in the rectum and even leakage with no sensation of the leakage) and interestingly, increased rectal sensitivity (which can cause inappropriate rectal muscle contractions forcing the stool out).

The proper evaluation of these problems requires a thorough history, which can be difficult given the sensitive nature of the problem and the reluctance of many patients to discuss their incontinence. A direct examination of the anus and rectum must be done to rule out mechanical problems such as inflammatory conditions or tumors (usually done as part of a colonoscopy). If indicated, ano-rectal manometry may then be performed to assess the muscle function and the sensation in the rectum.

Esophageal manometry

Esophageal manometry or motility is a procedure that measures the function and strength of the muscles of the esophagus or food pipe. The muscle activity is recorded while a person swallows to give an accurate picture of the process of transferring material from the top of the food pipe into the stomach. Combined with a swallow evaluation from the Phelps Speech and Swallow Centers, a complete picture of the muscle function from the mouth to the stomach can be obtained.

The procedure takes approximately 30 minutes to complete. The stomach must be empty for approximately 6 hours prior to the test. The patient’s nostril and throat are numbed with a topical anesthetic. No intravenous sedation is used as it could alter the muscle function, but the procedure is generally well tolerated. After appropriate anesthesia, a tube with pressure sensors is passed through the nose and into the mouth and then the esophagus. Subsequently, the patient is given controlled sips of water and the muscle activity is recorded both digitally and in graph form. After the procedure, preliminary results will be given to the patient. Driving is permitted after the procedure, but eating or drinking should be avoided for approximately one hour to avoid any difficulties secondary to anesthesia in the mouth.

Anorectal biofeedback & pelvic floor muscle retraining

Biofeedback is the process of training the mind to better control certain muscle functions.

Biofeedback enables the direct feedback to the patient of which muscles are being used for a given condition and whether they are being used appropriately. It also helps patients experience an improvement in their sensory response to stimulation. This technique has been shown to be valuable in the training and retraining of muscle function.

Biofeedback of the anorectum can benefit two separate conditions: Fecal Incontinence and Constipation.

Fecal Incontinence: This involves the unexpected and uncontrolled leakage of fecal material. It can occur in both men and women, can present at any age and may be due to a variety of conditions. Often, the anorectal muscles do not contract appropriately, thus allowing leakage. Appropriate feedback may increase the muscle strength and function.

Constipation: This condition involves delayed or prolonged time between bowel movements, with excessive straining required to have a bowel movement. This condition, too, can occur in men and women of any age. While the usual causes related to diet, fluid intake and level of activity, in many cases, the problem is caused or exacerbated by the anorectal muscles inappropriately contracting or closing, rather than opening, when a person attempts to have a bowel movement. Retraining of these muscles can relieve this, in effect, obstruction and ease the passage of the bowel movement.

In both incontinence and constipation, the difficulty may also be caused by or worsened by poor rectal sensation. If the appropriate signals that stool is present in the rectum are not transmitted, either incontinence, constipation or both may ensue.

Biofeedback of the anorectal sphincter involves the pelvic floor muscles that surround the pelvis and rectal opening. Two voluntarily controlled muscles, the external anal sphincter and the puborectalis muscle help control the sphincter. With proper feedback, the function of these muscles may be enhanced. In addition, the sensation inside the rectum can be trained through the use of feedback techniques.